Process for blanching nuts



Aug. 30, 1966 ,J. w. GARDNER PROCESS FOR BLANCHING NUTS 5 Sheets*Sheet 1Original Filed Aug. 6, 1962 INVENTOR.

BY JAMES W GARDNER FIG. 2

ATTORNEY Aug. 30, 1966 J. w. GARDNER PROCESS FOR BLANCHING NUTS 3Sheets-Sheet 2 Original Filed Aug. 6, 1962 INVENTOR. JAMES W GARDNER 774Whk q ATTORNEY 0, 1966 J. w. GARDNER 3,269,442

PROCESS FOR BLANCHING NUTS Original Filed Aug. 6, 1962 5 Sheets-Sheet 3JAMES W GARDNER B Y F IG. 4 WM, (MMPOAIJ 1. H mmmii ATTORNEY UnitedStates Patent 3,269,442 PRUtIESS FOR BLANCHING NUTS James W. Gardner,Tyrone, Pa, assignor to Seabrook Blanching Corporation, Edenton, N.C., acorporation of North Carolina Original application Aug. 6, 1962, Ser.No. 215,005, new Patent No. 3,196,914, dated July 27, 1965. Divided andthis application Dec. 30, 1964, Ser. No. 422,350 4 Claims. (Cl. 146-426)This is a divisional application of my copending US. application SerialNo. 215,005, filed August 6, 1962, now Patent No. 3,196,914.

This invention relates generally to nut blanching and more particularlyconcerns a novel process for quickly and efficiently removing skin fromshelled peanuts and the like without disturbing the natural oils in thenut.

According to present practice and as disclosed in US. Patent 2,558,899shelled peanuts and the like may be blanched by slitting their skins,dousing them in scalding water and then gently rubbing the skins otf bymassaging the nuts between opposing rubbing surfaces that areoscillating relative to one another. Alternative to passing the nutsbetween rubbing elements, U.S. Patent 2,702,574 discloses a method andapparatus for blanching nuts involving a series of vanes or bafflesdisposed in reversely inclined directions across a conveyor in positionto roll the nuts in zig zag fashion across the conveyor and so removetheir skins. Both of these techniques, while effective in blanchingnuts, involve excessive rubbing of the nuts and consume a relativelysubstantial amount of time. Furthermore, the high temperature of thewater in the scalding step adversely affects the oil structure of thenut reducing its shelf life.

Accordingly, it is a general object of the present invention to providean improved method for removing skins from shelled nuts.

Another object of this invention is to provide a novel method forblanching nuts without impairing their quality to any extent.

More particularly, this invention features a nut blanching processwherein nuts which have had their outer shells removed and their innerskins slit from end to end are subjected to a controlled drying step inwhich dehumidified air is circulated through the nuts and thetemperature of the nuts during this step is not permitted to exceed apredetermined level above which the oil structure of the nut would bealtered. From this temperature level the nuts are slowly cooled to roomtemperature and as a result the skins start to peel along the slits andaway from the nut. These skins are then completely removed by trappingand rolling the nut between a supporting moving surface and a fixedabutment inclined angularly with respect to the path of travel of themoving surface.

But these and other features of the invention, along with furtherobjects and advantages thereof will become more fully apparent from thefollowing detailed description of the invention with reference beingmade to the accompanying drawings in which:

FIG. 1 is a view in perspective of a nut blanching apparatus madeaccording to the invention,

FIG. 2 is a top plan view of the apparatus shown in FIG. 1,

FIG. 3 is a view similar to FIG. 2 but with the dispensing units andsupporting structure removed to show details of construction,

FIG. 4 is a view in end elevation of the apparatus,

FIG. 5 is a cross-sectional view taken along the lines 5-5 of FIG. 3,

FIG. 6 is a detail view showing a modification of the abutmentsupporting structure.

Patented August 30, 1966 In the practice of my invention, peanuts andthe like which have had their outer shells removed are passed through askin slitting apparatus such as that shown in my US. Patent No.2,699,806. In the above patent, the nuts are carried between a pair ofspaced and opposing knife edges which slit opposite sides of each nutfrom end to end. According to the present invention, once the slits havebeen made in the nuts they are transferred to a drying or dehydratingchamber wherein a continuous flow of dehumidified air is circulated overand around the nuts so as to dry their skins. This drying process causesthe skins to start peeling away from the nut along the slits. Once theskins have started to peel, the nuts are fed onto a blanching apparatuswhich will be described in detail below.

In carrying out the process of my invention, the large volume of freshdehumidified air which passes continuously around and over the nuts mayhave its moisture content removed by any conventional technique such asby the use of an activated oxide of aluminum, Al O commonly known asalumina, for example. A conventional air heating system may be employedto heat the air to the desired temperature. This air is then introducedto the drying chamber wherein the nuts are carried back and forth anddownwardly by means of a bank of conveyors stacked in staggeredarrangement one above the other with each conveyor depositing its chargeof nuts to the conveyor immediately below it. As the nuts descendthrough the drying chamber, the temperature gradually lowers until thenuts are discharged at approximately room temperature.

In carrying out this process, it is important to control the temperatureof the dehumidified air so that it does not exceed a maximum level abovewhich the oil structure of the nuts would be adversely aifected. It hasbeen found, that when processing peanuts, for example, a temperature ofapproximately F. is the maximum allowable temperature and that verysatisfactory results are obtained with a drying period of approximately38 minutes although this may be varied from 30 to 60 minutes accordingto the particular nuts being processed. In any event, the skins of thenuts are first slit, the nuts are then passed through the dehydratingprocess wherein the skins start to curl along the slits. This curling ofthe skins facilitates subsequent removal of the entire skin by passingthe nuts through the blanching apparatus to be described below.

By maintaining the temperature of the nuts below a predetermined levelwhich for peanuts has been found to be 160, for example, the shelf lifeof the nuts is substantially extended over nuts blanched by processesinvolving high temperatures which roast the nuts to a certain extent anddrive out or so alter the natural oils in the nuts that the quality ofthe nut is impaired. Nuts which have been heated to temperatures whichchange the oil structure of the nut are more brittle than the nutsblanched by the above process. Furthermore, such nuts are more readilysusceptible to becoming rancid if stored for any extended period.

Referring now to the drawings, the nut blanching apparatus for removingthe skins is generally organized about an upright table 10 which hasmounted at the top thereof and at either end rollers 12 and 14 aboutwhich is looped an endless conveyor belt 16. The belt 16 may have awidth of 36 inches, for example, with a substantially flat horizontalupper surface six feet or so in length. The belt surface employed in theillustrated embodiment is of a frictional character being fabricatedfrom reinforced rubber or other suitable material and preferably beingformed with a number of very small closely spaced truncated pyramids toprovide good gripping surface for moving nuts along the belt in thedirection indicated by the arrow of FIG. 3. The rollers areapproximately six inches in diameter and perhaps 37 inches or so inlength with their arbors 18 supported at their ends in bearing blocks20. Preferably the blocks are adjustable lengthwise of the table bymeans of screws 22 whereby the belt may be properly tensioned and thetwo rollers aligned in true parallel relation.

The upper reach of the belt 16 is fully supported throughout its lengthand width by an underlying panel (not shown) which provides a firmsmooth and flat supporting surface for the belt as it travels betweenthe rollers. The belt is moved by means of a variable speed motor 24mounted below the belt and driving the roller 14 by means of connectedpulleys 26 and 28 which drive a shaft 30 carrying a gear 32 in mesh witha chain 34. The chain in turn is looped about a sprocket gear 36 mountedon the end of the shaft supporting the roller 14.

Mounted to the table 10 and extending lengthwise thereof on oppositesides of the belt 16 are a pair of horizontal supports 40 and 42. Eachof these supports carries an inverted channel member 44 and 46 with themember 46 being mounted for lateral adjustment by means of bolts 48passing through lateral slots 50 formed in the support 40. The channelmember 44 on the other hand is mounted for longitudinal adjustment onthe member 42 by means of bolts 54 passing through longitudinal slots56. Extending diagonally across the belt 16 are a plurality of parallelabutments in the form of elongated tubings 58 with depending bafilemembers 60 attached lengthwise thereto. Typically, the leading surfaceof each baffie member is of an abrasive character which may be providedby a ply of grit paper 61 applied thereto or a strip of roughened metalof a type adapted to remove the skin from a peanut or the like which istrapped and rolled lengthwise along the battle.

The opposite ends of the tubings 58 are mounted on the channel members44 and 46 by means of vertical pins 62 spaced evenly along the topsurface of each member. Each of the pins is threaded and provided withtwo lower nuts 64 and 66 with a third nut 68 attached to the upper endof the pin 62 for clamping the end of the tubing in place. It will beunderstood that by properly rotating the nuts 64, 66 and 68 theefiective height of the tubings 58 may be adjusted relative to the ,topsurface of the belt 16. It will also be appreciated that the angularposition of the tubings across the belt 16 may be varied by looseningthe bolts 48 and 54 and manually shifting the member 46 laterally andthe member 52 longitudinally until the desired angle of the tubings 58is achieved. By mounting the tubings on the pins 62, all of theabutments, which may be 24 in number extending parallel to one another,may be adjusted simultaneously. Once the proper setting is reached, thebolts 48 and 54 are again tightened to clamp the channel members 44 and46 firmly against their supports.

It will be noted in FIG. 3 that the baffles 60 along one side do notextend for the entire width of the belt 60, but rather terminate twomore inches from the left hand edge of the belt as viewed in FIG. 3. Theright hand end of the bafile 60 extends substantially to the edge of thebelt so that nuts fed onto the belt between each of the abutments willbe moved forwardly and to the left until they reach the dischargeportion of the belt which extends along the left hand side of the belt.In practice, a guard 70 extends along opposite sides of the belt and maybe in the form of a rubber strip 72 attached to elongated metal strips74 which rest on top of the abutments. The rubber strips depend fromtheir supporting elements to the surface of the belt 16 therebypreventing any stray nuts from rolling off the conveyor system.

As best shown in FIG. 3, the abutments are mounted for rotary adjustmentabout their longitudinal axes whereby their abrasive, nut-engagingsurfaces may be arranged to define a selected acute angle with respectto the belt 16. It will be understood that nuts travelling along withthe moving belt will be trapped within the acute angle defined by thebaffles 60 and the belt 16 and will be rolled along lengthwise ofv thebattle and diagonally of the belt towards the left hand discharge partof the belt as shown in FIG. 3. Depending upon the size and thecharacter of the nuts that are being blanched, the baffles may beadjusted to whatever angle produces the best blanching action. Asillustrated in FIG. 3 each end of each abutment tubing 58 is threaded at76 and received in the tapped end of a sleeve 78 which is pivotallymounted about a vertical axis to the pin 62. The threaded end of thetubing 58 is also provided with a jam nut 80 which, when backed off,will permit the tubing to be rotated 360 about its longitudinal axis.When the selected angular position is reached, the jam nut 80 istightened up against a nut head 82 formed on the inner end of the sleeve73, thereby locking the tubing in position. It will be appreciated thatwhile both ends of the abutments may be tightened in the desired angularposition for maximum rigidity sufficient positioning may be obtained bymerely locking one end of each abutment. By providing a full 360adjustment, the frictional surface of the baffle 60 may be raised into ahorizontal position to permit periodic cleaning of that surface.

In FIG. 6 there is illustrated a modification of the supportingstructure for the abutments and, in this embodiment the channel members44 and 46 are provided with vertical adjustment screws 84 which arethreaded to the channel members with their lower ends bearing againstthe upper surfaces of the horizontal supports 40 and 42. Thisarrangement permits all of the abutments to be raised or loweredsimultaneously by merely rotating the screws 84 one way or the other asdesired.

Referring again to the principal embodiment and more particularly toFIGS. 1, 2 and 4, there is illustrated a novel feeding arrangement fordispensing separate streams of nuts at selected locations on the belt16. As shown, an overhead bridge 86 is mounted to the table 10 by meansof a pair of vertical brackets 88 located at each end of the table 10.Each pair of brackets 88 supports a channel member 90 which extendstransversely across the belt 16 in general parallelism wit-h the rollers12 and 14. Mounted between the channels 90 for transverse slidingmovement above the belt 16 is a frame 92 comprising a pair of spacedchannel members 94 rigidly fixed in spaced parallel relation to oneanother by a cross piece 96 welded thereto. Slidably mounted between thechannel members 94 is a battery of vibratory dispensing units 98 whichare adapted to feed nuts down an inclined ramp 100. Each vibratoryfeeder, it will be noticed, is formed with a plurality of spacedparallel troughs 102 which are aligned with troughs 104 formed in theramps 100. These troughs are evenly spaced to correspond with thespacings between the abutments, so that when the lower ends of the rampsare positioned over the abutments in the manner illustrated, the nutscoming down the ramps will be deposited on the belt between adjacentabutments. It will be appreciated that with the above mountingarrangement the vibratory feeders, as well as their discharge ramps, maybe adjusted longitudinally and laterally relative to the surface of theconveyor 16, to accommodate changes in the diagonal orientation of theabutments. Also, the nuts may be deposited at any selected positionalong the lengths of the abutments to vary, as desired, the duratron andamount of rubbing contact with the abutments. As shown in the drawings,the feeders are arranged to discharge the nuts approximately at themid-position of the belt with the feeders being positioned at the farleft hand side of the bridge 86. By moving the bracket 92 to the rightalong the channels 90, the feeders will also be moved to the right sothat the nuts will be deposited further along the abutments. This willincrease the path which must he travelled by the nuts before reachingthe left hand discharge path. In order to re duce the path of travel ofthe nuts, the feeders may be shifted to the right hand side of thechannels 90 and their positions reversed so that the ramps 100 will beinclined downwardly to the left rather than as illustrated. In thisfashion the nuts may be deposited closer to the left hand discharge sideof the belt. It is thus possible to provide for any selected diagonalpositioning of the deposit points of the ramps 100 as well as toaccommodate for shifting of the abutments relative to the belt 16.

Each of the vibratory feeders 98 are fed from an overhead hopper 106through conduits 108 provided with adjustable elbows 110. The hopper issupported for lateral and longitudinal adjustment by means of a pair ofsupporting tracks 112 which engage lips 114. The tracks 112 are rigidlyconnected by means of a pair of slotted cross members 116, which inturn, are connected to an overhead supporting piece by means of bolts sothat the tracks 112 may be moved laterally by means of loosening thesebolts. The hopper 106, of course, may be moved longitudinally of thetracks 112 to accommodate the positioning of the vibratory feeders 98throughout their full range of adjustment.

It will be appreciated that the process and apparatus described hereinare particularly efficient and useful in that the nuts which areblanched according to the invention will not be damaged and will emergein a fresh whole condition. In the trade, blanched nuts that have few,if any, splits and which have a potentially long shelf life, command amuch higher price than those nuts which contain a high percentage ofsplits and which cannot be stored for any extended period. It will alsobe appreciated that the apparatus described herein will accommodatevarious sizes and grades of nuts as well as different kinds of nuts. Byproviding a full range of adjustment for the various components in theblanching apparatus, optimum performance is obtainable for any blanchingsituation. The adjustment features of this incention provides maximumcontrol over the blanching process to eliminate as far as possiblesplitting and crushing of the nuts as they pass along the abutments.

While the invention has been described with particular reference to theillustrated embodiments, it will be understood that numerousmodifications thereto will appear to those skilled in the art. It willalso be understood that the invention illustrated and described hereinhas been made by way of illustration and should not be taken in alimiting sense.

Having thus described my invention, what I claim and desire to obtain byLetters Patent of the United States is:

1. A process for removing skins from shelled nuts comprising theconsecutive steps of:

(1) first mechanically slitting said skins from end to end of the nuts,

(2) passing the slitted nuts through a drying chamber in which flows astream of dehumidified air having an elevated temperature below thatwhich would alter the oil structure in said nuts,

(3) gradually dry cooling said nuts and thereby causing said skins tocommence peeling away from said nuts along said slits, said skinsforming curls on each side of said slit line and (4) finally rollingsaid nuts in a dry condition between lightly abrasive surfaces to removesaid skins entirely from said nuts, said curls serving as a purchase forsaid abrasive surfaces.

2. A process according to claim 1 wherein said elevated temperature isapproximately 160 F.

3. A process according to claim 2 wherein said nuts are dried and cooledfor a period ranging from 30 to minutes.

4. A process for removing skins from shelled nuts, comprising theconsecutive steps of (1) mechanically scoring said skins,

(2) dry heating said nuts to approximately F.

for a period of 30 to 60 minutes,

(3) dry cooling said nuts to ambient temperature to thereby cause saidskins to commence peeling away from said nuts along the score line, saidskins forming curls on each side of said slit line and,

(4) finally moving said nuts in a dry condition against an abrasivesurface to remove said skins entirely from said nuts, said curls servingas: a purchase for said abrasive surfaces.

References Cited by the Examiner UNITED STATES PATENTS 2,558,899 7/1951Green 146230 2,995,166 8/1961 Burley et a1 146-227 3,077,217 2/1963 Hind146-32 X ROBERT C. RIORDON, Primary Examiner. WILLIE G. ABERCROMBIE,Examiner.

1. A PROCESS FOR REMOVING SKINS FROM SHELLED NUTS COMPRISING THECONSECUTIVE STEPS OF: (1) FIRST MECHANICALLY SLITTING SAID SKINS FROMEND TO END OF THE NUTS, (2) PASSING THE SLITTED NUTS THROUGH A DRYINGCHAMBER IN WHICH FLOWS A STREAM OF DEHUMIDIFIED AIR HAVING AN ELEVATEDTEMPERATURE BELOW THAT WHICH WOULD ALTER THE OIL STRUCTURE IN SAID NUTS,(3) GRADUALLY DRY COOLING SAID NUTS AND THEREBY CAUSING SAID SKINS TOCOMMENCE PEELING AWAY FROM SAID NUTS ALONG SAID SLITS, SAID SKINSFORMING CURLS ON EACH SIDE OF SAID SLIT LINE AND (4) FINALLY ROLLINGSAID NUTS IN A DRY CONDITION BETWEEN LIGHTLY ABRASIVE SURFACES TO REMOVESAID SKINS ENTIRELY FROM SAID NUTS, SAID CURLS SERVING AS A PURCHASE FORSAID ABRASIVE SURFACES.